Speaking of Randur, here's a little something in the menu that he pointed out to me: Advanced->Rendering->Info Displays->Avatar Rendering Cost
What it does is put on display how much effort is going into rendering your (and your friends') avatars, using both numbers and a green (good) to red (Danger, Will Robinson!) color scale. Linden Labs itself admits that it's a rough estimate, and leaving it on all of the time will actually contribute to your performance issues, but it's still a potentially useful tool.
Consider Averlast, for example. I've documented cases of killer lag on fight night. Sometimes it seems like SL itself is a worse opponent than the fighter in the other corner. A tool like this could help our fighters streamline themselves as much as possible, to the benefit of everyone.
Of course, the audience is the uncontrollable factor. People want to look their best on a night out, after all. Will the introduction of ARC into the mix of SL introduce mandatory maximums at events like ours? It will be interesting to see how different places handle it.
Linden Labs has the full details here.